1. Field of the Invention
For the purpose of screening the noise of aircraft engines during the test run, use is made of soundproof hangars that accommodate more or less the entire aircraft. The hangar opening is frequently left completely open, the hangar being oriented such that it screens the emission to the residential side, whereas the opening is directed toward the noise-insensitive side. There are cases, however, in which it is also necessary to take sound-damping measures on the opening side. This means that the opening has to be capable of being closed completely or partially, or that the engines, as sound sources, have to have the walls of the hangar projecting laterally beyond them toward the opening side in order for the free acoustic emission angle to be small enough.
2. Description of the Related Art
In the case of a known soundproof hangar (GB-1089630) with a wide entrance opening for aircraft, the air inlets are arranged in the side walls of the hangar. They are subdivided by a multiplicity of ribs which are located perpendicularly with respect to the side wall and cause the inflowing air to flow transversely with respect to the longitudinal axis of the hangar or the longitudinal axis of the engines. This has considerable disadvantages for those engines which react sensitively to non-uniform incoming flow, for example those which are provided with a bypass. If, as a result of the air guidance contained in the wall, they are subjected to non-uniform incoming flow, they may be damaged and possibly even destroyed.